Fabric let back means for looms



Dec. 29, 1953 H. B. GosNELL 66215115 FABRIC LET BACK MEANS Fox Lo'ous Filed sept. 22, i951 2 sheets-sheet 1 u w 3 5 rO n/i 1 1 1 w G m l www?. u nl/IN IIII O- im 9 4 V 1 u 6/ m I l. Nillllll l l1 |ll .1||| !|\H||1l|M||||AMMMHML .j n Y u E v m Il O J I. mw Z, w M 5 9 7 6.... 65 .l 4 3 7 6 ll .JJRIIII! 7 6 7 HARDY B. Gos/vE/ L BY A TTORNE Y Dec. 29, 1953 H. B. GosNELL 2,664,115 FABRIC LET BACK MEANS FOR Loous v Filed sept. 22, 1951 2 sheeesssnbt 2 IN VEN TOR. HARDY B, GOSNELL A TTORNE Y Patented Dec. 29,

UNITED STATES PATENT OFFICE FABRIC LET BACK MEANS FOR LOOMS Hardy B. Gosnell, Greenville, S. C.

Application September 22, 1951, Serial No. 247,860

13 Claims. (Cl. 139-313) This invention relates to improvements in looms for weaving, and more particularly, to a fabric let back mechanism applicable to such looms.

It is a general object of the invention to devise a mechanism for letting back the fabric take up means of looms so as to slacken the warp threads for the purpose of eliminating insofar as is practicable, the stopping and/or set marks which occur during the weaving of some materials and which seriously detract from the quality thereof.

It is a more specific object to devise a means which may function automatically as the loom is stopped to let back the fabric take up means for a relatively extended degree so that the Warp threads may not become stretched during stopping periods of several minutes, and which shall also be operable with small effort on the part of the weaver to reset the take up and thus the warp tension as may best serve for resuming the weaving function without introducing a perceptible and objectionable mark incidental to the stopping and starting of the loom.

It is a further object of the invention to devise safety means functioning automatically and incidental to the resetting of the take up means the purpose of which is that of making it impossible to start the loom before the warp tension has been properly reestablished.

Other objects of the invention will become apparent from the following more detailed disclosure.

Heretofore fabric let back means have been made a part of some looms, but their function has, for the most part, been circumscribed to one for letting the cloth back at most a few picks, that being more or less incidental to the repair of a faulty pick or the like. While weaving certain materials in which the warp threads are of a stretchy nature, it has been experienced that at each stop of the loom for more than a very brief interval, the point of stopping and restarting has been all too apparent in the finished fabric and its value obviously diminished thereby. These stop marks or set marks as they may be more accurately termed, become more serious if the loom is stopped for longer periods of time and thus the fabric fault occasioned by the stop is a function of the period of time during which the loom is at rest. With some warp materials a stop of as much as five minutes is relatively serious.

In attempts to alleviate these troubles, it has been found that a let back of the fabric for only a few picks has virtually no eii'ect. Tension must be slackened to a point where stretching of the Warp threads becomes negligible even over extended periods of time. To accomplish that a reverse rotation of from one-half to close to a full revolution of the conventional ratchet or pick wheel by which the fabric take up is advanced has been found necessary.

The present invention is characterized by provision of a let back control means permitting the ratchet wheel to be lreleased by its feed and stop pawls whereupon the tension in the cloth and warp threads causes reverse rotation of the parts to a point where a so-called indicaton subject matter of my copending application Serial No. 191,900, now United States Patent 2,591,538, stops against a part of a resetting means.

The loom operator has only to press a convenient foot pedal to reset the device and to reestablish Warp tension before pulling the shipper lever or otherwise starting the loom.

Preferably, a safety means is employed by which the shipper lever is locked in loom stopped position. This may comprise a latch which makes engagement when the shipper lever moves to stop the loom and which is also controlled by the resetting pedal or means functioning therewith, to release the latch as the tension is reestablished. The loom may thus be started only when conditions are correctly set preparatory to a continuance of weaving.

The invention will now be described in detail by reference to one preferred embodiment which it may take as illustrated in the accompanying figures of drawing wherein:

Fig. 1 is a left end elevation of as much of a conventional loom as is necessary to show the application of the invention thereto.

Fig. 2 is a front elevation of those parts shown lll Fig. l. n y

Fig. 3 is a view similar to Fig. 1 showing certain parts after let back has been effected.

Fig. 4 1s a section at line t-s, Fig. 1, showing details of the indicator and adjacent parts.

Fig. 5 is a detail view of the feed pawl lifting means. v

Now referring to Figs. 1, 2 and 3, looms of the type to which the invention may be applied have as a part thereof some form of fabric take up, a common example of which employs a fabricengaging and advancing roll ID rotatable upon a shaft il and driven through a train of gears including a pinion l2, a gear I3 and a suitable number of intermediate gears I4 and l5, change# able asand for a. purpose well known to those skilled in the art. These gears |4 and i5 are mounted on a stub shaft I6 fixed to loomside I1.

The pinion I2 is fixed at one end of a shaft I3 rotatable in a bearing I9 at the loomside and to the other end of which is also xed a ratchet or pick wheel 20. Motion taken from any convenient moving part is employed to advance this ratchet wheel; as here shown, an arm 2| fixed to the end of rock shaft 22 oscillates a pivoted lever 23 through a link 24. At its upper end lever 23 has pivoted thereto at 25 a feed pawl 26. The latter engages the teeth or the ratchet whe-ei and advances it step by step as the lay of the loom* swings to and fro. The lever arm andthe length of link 24 are capable of being varied to provide a longer or shorter picking movementV as fre# quired.

A stop pawl 21 is pivoted at 28 to a stud extending from the loomside and serves to maintain the ratchet wheel against reverse movement. Each of these pawls 25 and-21 =is' preferably caused to engage the 'teeth of the ratchet wheel by being pressed thereon by a spring;

A hand wheel 29 is attached to the extreme end of the shaft I8` and may be used toturn the roll I manually .when desired.

Since the automatic let back of the fabric is initiated by the stopping of the loom, either by the weaver or due to action of one of the stop motions, that means from which the let back action is controlled will be briefly described. A shipper lever 30is pivoted atSI to the loom framework and at its lower end has connected at 32 a curved link 33 which attaches at its opposite end by a pin 34 to an arm 35 fixed on that end of starter shaft 36. Movement of shipper lever 3D toward the front of the loom engages a clutch orY otherwise connects power to the mechanism and also, through link 31, releases a brake. Movement to the rear affects theparts to cause stopping. Lever 30 may be engaged by hand or may be pressed to the rear by lever 38 and other stop motion parts, all in a manner understood by those conversant with the art.l I

When the looml stops the stop pawl 2l is withdrawn from-the teeth vof the wheel 2D by action of a slotted link 39 also attached at pivot pin 34, see Fig. 3. In'the event the loom is set for let back of the fabric, pawl 26 is also withdrawn by mechanism presentlyv to be described, so that t there is then no restraining influence at all upon the take up means to prevent its reverse rotation under the tension of the warp.

Pawl 26 has a lifting arm or ringer 40 against the upper edge of which a means attached to form an operative portion of the shipper lever presses for the purpose of raising the pawl from its ratchet wheel. The shipper lever carries a block 4| clamped to it by a bolt or screw 42. This block is bored for the reception of a rod 43 bent angularly to provide a laterally extending Contact portion 44 overlying the finger 4|). The rod extends in the opposite direction from block 4| and has a control knob 45 attached to its upper, forward end. As the shipper lever is swung to stop the loom, Fig. 3, the rod 43 and contactV portion 44 are swung to a position in which the latter part presses downwardly on finger ci! and rocks the pawl to lift it to a disengaged position.

As more clearly shown in Fig. 5, the rod may be swung manually to and from positions in one of which it is effective to lift pawl 26 and another in which it becomes inactive. The block is slotted horizontally rnd vertically as at 46 and 41 and a pin 48 extending from the rod may be engaged selectively in either slot to hold the rod in position. When in the horizontal slot the parts are active to raise the pawl, and when vertically disposed, they are ineiiective for that purpose. A spring 49 under compression between the block and a collar 50 maintains the prts in either position, but permits disengagement of the pin with a Slot by manually pushing against knob 45 whereupon the projection 44 may be swung to and latched in either of its positions.

Assuming that the pawls are both released as above explained, the ratchet wheel will rotate reversely and that reverse movement is limited by a stop and resetting arm 5| having a laterally bent end 52, and a means hereinafter referred to as an indicator, and which is the subject matter of my copending application, above mentioned.

As shown in Fig. 4', the indicator is adapted to be removed at will and is operably held in place as a hooked end 53 of rod 54 is mintained seated in a groove in hub 55 of the ratchet wheel 20. Rod 54 is oppositely bent at its other end as at' 5G to straddle the toothed rim of wheel 20. A short portion 51 of the rod extends parallel to that at the opposite side of the ratchet wheel and a spring pressed, tooth engaging member 58 is apertured to slide radic lly of the wheel along the rod. This member is centrally slotted to present an angular surface which approximately conforms to the baci: angl-3 of a ratchet wheel tooth so that it may be pressed outwardly by the teeth as they pass while the tcke up action is in progress. Springs 539 and 60 maintain the member in engagement with the teeth so that when let back occurs, the entire indicator will be carried around by the wheel 2|! until the member 58 strikes against bent end 52 of arm 5|. Of course, if tension in the fabric and warp is relaxed to the point where it mcy not overcome the friction of the gearing, bearings, etc., then the let back parts may not move to the fullest extent theoretically possible. The ratchet wheel teeth may pass the member 58 in one direction only and vice versa. Thus when it is desired to restore the take up parts to a position in which the warp tension shall be a proper one for starting the loom, arm 5| is desirably carried around to a position close to that shown in dot-and-dash lines, Fig. 3,

The indicator is provided with a stop means which functions in conjunction with the hub 6| of stop pawl 2l. The U-shaped or bent part 56 has welded or otherwise attached to it a lug 62 tapped for the reception of a stop screw B3. This screw may be adjusted and is held in position by the usufl lock nut. It forms, in conjunction with that relatively fixed part of the mechanism with which it cooperates, a reference point by which the return of the indicator may be gauged.

At certain times itis desired to rotate shaft |8 through several revolutions in*l a direction in which the ratchet wheel teeth will not pass the indicator: at such times then enge gement of the latter with arm li! would prevent the turning of the wheels 2Q and qfor more than a part revolution. To take care of thatsituation, the indicator is made quickly detachrble. It would be quite within the realm of possibility to lift the member 58 from the wheel teeth, but it is equally simple to grasp the looped end 56 of the rod 54 and to push radially inward until the hook 53 may be released from hub 55 and thus the indicator may be removed bodily. The hand wheel may then be used to let back thel fabric es far as desired after which the indicator may be replaced. If

threaded into the lower forward part of the loom- Side Il.

A pinion @t having a iiange 6l' is freely rotatable on shaft iii and it is this iiange of the pinion to which an enlarged end 68 of the arm I is attached. A rack 69 is bolted or otherwise connected to a slotted guide plate 16 and is restrained to mesh with the pinion by the engagement of the slot i8 about shaft I8.

A bent rod il is threaded into the lower end of rack 69 and at its other end is adjustably held by opposed nuts 'l2 within a swivel eye 13 the stem lll of which passed through an opening at the end of arm l5 which is, in fact, a branch of the larger or main arm 65 which is preferably integral with a hub 'i6 and the pedal 612. rThe pedal, arm 65, rod 1I and the rack are normally maintained in an uppermost position by a spring 'El connected at one end to a lug on arm 65 and at its other end to a pin or other fixed anchor point on loomside il. At such time theraok will be in uppermost position with the lower end of the guide slot I6 against the shaft i8. The length of the slot and rack is at least suicient to rotate the pinion, and with it, arm 5i, which frictionally engages or pushes against the indicator to move it through a sufficient angle to return it and the ratchet wheel until the indicator assumes the dotand-dash line position, Fig. 3.

With so much of the device as has been described to this point, the loom may be stopped whereupon the fabric will automatically be let back and may be reset for restarting the loom. However, without more, the loom may also be started without resetting the take up in which event the warp tension would be entirely inadequate and imperfect fabric would be woven. To obviate such possibility a safety means is incorporated by means of which there can be no loom operation until the warp tension has been restored.

A lever lt is pivoted at 32 to the lower end of shipper lever 36 and has adjacent one end a twisted, apertured part I9 through which projects a rod 86. At its other end it is provided with a notch 8i engageable with a pin 82 or other fixed part so that when the notch embraces the pin, shipper lever 30 may not be moved. However, as pedal 64 is pressed downwardly to reset the mechanism, rod 36 connected at its lower end to a swivel eye 83 the stem of which passes through a hole in arm 65, draws downwardly on the forward end of lever 'i8 thereby raising the opposite end and the notch 8l away from pin 82. Then the shipper lever may be moved forwardly to start the loom. A spring 84 under compression between a collar 85 and the end 'i9 of the latching lever tends to force it about the pivot 79 so that whenever the pedal is raised and shipper lever 36 is moved to stop the loom, the notch 8| must engage pin 82. A second collar 85 above the end 19 contacts the top surface of that end and transmits the downward pull of the arm 65 as shown in the dot-and-dash position of the parts, Fig. 3.

If it is desired to limit the let back movement to something less than that provided by the length of the slot in guide plate l0, a stop, n

e. g., pin 81 shown dotted in Fig. 3, may limit the upward or return motion of the pedal and arm and then byadjusting the length of rod i l, the return of the arm 5| may be limited as desired.

While it may suilce to return the indicator toA a point where it will stop ragainst the hub 6I as heretofore described, that does necessitate watchingthe mechanism and pushing pedal 64 downmore carefully. Preferablya stop screw 88 is threaded into pedal 64 or arm 65 and an enlarged head of that screw is brought into contact with the iioor on which the loom is set, or with'a wear plate attached to that floor. That limits the lextent to which the pedal may be depressed and thus the tension to which the warp threads shall be subjected at the resetting movement. In some cases it may be more satisfactory to return the take up means to a point where the indicator is some distance short of the point where the'stop screw 63 would contact hub 6l.

In operation it is to be assumed that the pawl lifter 43 is set horizontally to engage the finger 46. As the loom is stopped either by the weaver or through an automatic stop motion. the shipper lever 30 will be moved to the position of Fig. 3. That raises pawls 26 and 2l so that the ratchet wheel is free'to rotate reversely. The warp and fabric tensions will be relieved and, of course, movement may continue until the indicator is stopped against the lateral extension :62 of arm 5l. Normally the tendency to stretch the warp threads will be lessened to a point where with normal periods of non-operation, at least, the actual effects of warp elongation will be negligible. The latching safety means will at the lfull movement of lever 36, lock the latter in loom stopping position.

When the loom is to be restarted the weaver first depresses pedal 64 either to a point where stop 88 limits its travel or to a desired value of warp thread tension as determined by observation of the indicator.` The loom may then be started since depression of the pedal also releases the safety latch. After that the pedal may be released whereupon it acts under spring 'H to repositi'on the parts preparatory to performing the same function at the next loom stop.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. The yinvention is, therefore, not to be limited to the precise details described, but is intended to embrace all varia-tions and modiiications thereof falling within the spirit of the invention' and the scope of the claims.

I claim: l

1. For a loom having a fabric take up means including a roll'and means to drive said roll including a gear train and a ratchet wheel, a feed pawl and ay stop pawl 'for said ratchet wheel, and a loom knock off .means including a shipper lever, a fabric let back means which comprises means to disengage said pawls from theratchet wheel as the loom is knocked off, an indicator carried by the ratchet wheel past which the wheel may move in its rotation incidental to taking up fabric, but further adapted to be carried around with the wheel when thelatter rotates reversely, and means including a foot pedal under control of the loom operator for resetting the ratchet wheel to a ypredetermined position throughysaid indicator.

,2, Fgraloom having a fabnctakeupmeans includinga roll'and means to'- drive;saidrcll'irr-V cludinga gear trainianda ratchet'wheel.' aifeed pawl and a stop pawl' for saidratchetiwheelf and" a loom'knock off'means including -a, shipper lever,

a fabric let back means which comprises means to disengage said pawls from .theratchetjwheel as the loom is knockedjoflg'an .indicator carried by the ratchet wheel past which the wheel'may move in its rotation'incidentalitotaking up' fab'- ric, but furtherV adapted tobe carried" around with' the Wheel whenthe latter rotates reversely,v and'means for limiting the' reverse rotation of 'the' ratchet wheel'andthus'the degree of let back of the fabric and for resetting the' take up ,meansz toa predetermined 'loom startingt position which includes a meshing rack and .pinion, an arm attached for' movement 'with' saidpinion `and in. position to Vlimit movement of -saidindicator and. to'carry it and the ratchet wheel varound Withitl connected and resilient'means to urge the rack.

and pedal toward one extremeposition to be occupiedthereby,

4. For a loom having ja fabrictake'up means 'i including a roll'and means to drive said 'rollincluding a gear train and a ratchet wheel, a feed pawl and a stop pawl'for said ratchetwheel, and a loom knock off means including ashipper lever, a fabric let back means which comprisesa link connected to said stop pawl Vand movable `by said shipper lever when itis. in loom stopping position for disengaging th'epawl'from the' ratchet.

wheel, other means carried 'bysaid shipper lever and effective upon the. feed pawl'for disengaging it from the ratchet'wheel 'substantially simultaneously with the disengagement ofthe stop pawl,

an indicator carried by the ratchet wheel past.

which the-wheel may progresses itis'rotated incidentally to takinglup the fabric, Vb"ut.so devised as to be carried around withlfth'e Wheel when the latterrotatesreversely incidentally to its let back function, and means includingafoot edal under control of the loom operator for resettingthe ratchet wheel, and thus the fabric tension, to a predetermined position andtension value through' thev said. indicator;Y

5. For a loom having afabric .ta-ke up means including a roll and means to drive said rollincluding a gear train and a ratchetv Wheel afeed pawl and a stop pawl for said ratchet .wheeL and a loom knock off means including a, shipper lever, a fabric let back means which comprises a link connected to'said stop pawl and movable by said shipper lever when' it is in loom stopping position for disengaging the pawlfrom the ratchet Wheel, othermeans carried by saidshipper lever and effective upon the .feed pawl vfor disengaging it from the'ratchet wheel substantially simultaneously with the disengagement of the stop pawl, an indicator carried by the ratchet wheel past which the wheel may progress as it' is rotated incidentallytotaking upA the fabric,

but so devised as to be "carried around with the wheel when the `-latter-rotates reverselyincidentally to its let back function, andk means for limiting the reverse rotation of the ratchet wheel and thus the degree of let back of theffabric and for Y resetting the takeup-means to avv predetermined loomf` starting positioni which: includes-ameshing rack v'an'd`pinion, an arm attached for movement with said pinionand in positionto limit movement of said indicator and to carry it and the ratchetv wheel`aroundwith it when rotated, and means actuated by the loom operator for reciprocating said rack thereby to rotate the pinion and to' swing the attached arm through that arc required to reset the mechanism.

6. For a loom having a fabric take up means including a roll and means to drive said roll including a gear train and a ratchet wheel, a feed paWl and a stop pawl for said ratchet wheel, and a loom knock off means including a shipper lever, a fabric let back means which comprises means to disengagesaid pawls from the ratchet wheelas the 1oom` is knocked off, an indicator carried by the. ratchet wheel past which the wheel may move in its rotation incidental to taking up fabric, but further adapted to be carried `around with the wheel when the latter rotates reversely, and means under control of the loom operator for resetting the ratchet wheel to a predetermined position through said indicator, and a safety means for locking said shipper lever in a loom stopping position, and other means operable through said means for resetting the indicator and ratchet wheel to release said safety means.

'7. For a loom having fabric take up and let back means, a safety latch automatically operable when the loom is vknocked off to prevent movement of the shipper lever to loom starting position until the let back fabric has been retensioned, a foot operated means for resetting the let back devices and reestablishing tension in the fabric and linkage therefrom to the safety latch for releasing it simultaneously with the resetting function.

8. For a loom having a shipper lever, fabric take up and let back means, a safety latch pivoted to said shipper lever and engageable with an abutment for maintaining the shipper lever in a loom stopping position, a food pedal and means operable therefrom .for resetting the fabric let back means 'to reestablish tension in the fabric and warp threads preparatory to resuming weaving, and a link interconnecting said pedal and safety latch for releasing it as the pedal is operated to reestablish proper loom starting conditions.

9. For a loom having a fabric take up means including a roll and means to drive said roll including a gear train and a ratchet wheel, a feed pawl and a stop pawl for said ratchet wheel, and a loom knock on means including a shipper lever, a fabric let back meanswhich comprises means to disengage said pawls from the ratchet Wheel as the Yloom is knocked off, an indicator carried by the ratchet wheel past which the wheel may move in its rotation incidental to taking up fabric, but further adapted to be carried around with the wheel when the latter rotates reversely,and means under control of the loom operator for resetting the ratchet wheel to a predetermined position through said indicator, and means `for limiting the resetting movement and an adjustment therefor to limit the tension which may be imposed upon the Warp threads preparatory to restarting the loom.'

l0. For a loom having a fabric take up means including a roll and means to drive said'roll including a gear train and a ratchet wheel, a feed pawl and-a stop'pawl'for said ratchet wheel, and a loom knockoi means including a shipper lever,

a `fabric let back'means which comprises means to disengage said pawls from the ratchet wheel as the loom is knocked off, an indicator carried by the ratchet Wheel past Which the Wheel may move in its rotation incidental to taking up fabric, but further adapted to be carried around with the wheel when the latter rotates reversely, and means for resetting the ratchet wheel and reestablishing tension in the warp threads which comprises a foot pedal, spring means to urge it to one extreme position, and a pedal stop means for limiting its travel in the direction of resetting movement thereby to limit the value of the tension that may be applied to the Warp threads preparatory to restarting the loom.

11. For a loom having a fabric take up means including a roll and means to drive said roll including a gear train and a ratchet Wheel, a feed pawl and a stop pawl for said ratchet wheel, and a loom knock oi means including a shipper lever, a fabric let back means which comprises means to d'isengage said pawls from the ratchet Wheel as the loom is knocked oif, an indicator carried by the ratchet Wheel past which the wheel may move in its rotation incidental to taking up fabric, but further adapted to be carried around with the wheel when the latter rotates reversely, and means for resetting the ratchet Wheel and reestablishing tension in the warp threads which comprises a foot pedal, a pinion concentrically pivoted With respect to said ratchet Wheel, an arm movable with said pinion and positioned to act as a stop for said indicator and adapted upon rotation of the pinion to effect return of the indicator and ratchet wheel to a loom operating position, a rack guided for meshing engagement with said pinion and a connecting link from said rack to the pedal, and means for limiting the eiect of said pedal and rack in returning the arm after a resetting movement thereby to limit the extent of fabric let back.

12. Mechanism as defined in claim 11 wherein the link from the pedal to the rack is adjustable as to its length.

13. For a loom, a let back means comprising means for releasing feed and stop pawls for a fabric take up advancing ratchet wheel, an indicator and stop means therefor to limit the extent of let back, and pedal operated means to reset said indicator and simultaneously therewith the position of said ratchet wheel and take up means advanced thereby preparatory to restarting the loom.

HARDY B. GOSNELL.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,854,017 Burdett Apr. 12, 1932 2,591,538 Gosnell Apr. 1, 1952 

